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L. H. ALLEN AND JOHN B. lWILFORD, 0F TAMAQUA, PENNSYLVANIA.

Letters Patent No. 80,698", dated August 4, 1868.

IMPROVEMENT 1N STEAM-ENGINE suns-VALVES.

TO ALL WHOM IT MAY CONCERN:

Be it known that we, L. H. ALLEN and JOHN ,B.-WILFORD, of Tamaqua, in the county of Schuylkill, and State of Pennsylvania, have invented a new and useful Improvement in Steam-Valves and Valve-Motion; and we do hereby declare thatthe following is a full, clear, and-exactdescription thereof, which 'will en-.ablethose skilled in the art to make and use the same, reference being had tothe accompanying drawings, forming part of this specification. v

This invention relates to an improvement in sliding steam-valves, and to .the method by which they are operated; and it consists in the arrangement of the bars formed upon the slidefvalve, with the exhaust-openings and passages, whereby the stroke of the valve is completed, so as to make the maximum opening of the ports, as will be hereinafter' described.

Figure lis a horizontal section of the face-of the main cylinder, and of the auxiliary cylinder, showing the apertures through which the exhaustfsteam passes from themain cylinder to the auxiliary cylinder', also the steam and exhaust-ports, the section being through thepline ne x of iig. 2,v wi th the valve removed.`

Figure 2 is a vertical section of fig. 3, through the line y y.

Figure 3 is a longitudinal vertical section through the line z z of fig. 1.

Similar letters'oi` reference indicate corresponding parts. I

A is the main or engine-cylinder. y

B isthe auxiliary cylinder.

C is the slide-valve.

D4 is the steam-chest. l y

E is a piston in the auxiliary cylinder, the rod of which, F, is attached t0 one cndof a vibrating-lever, Gr, which lever is pivoted to astand on the main cylinder, as scen atvz. l i

The valve-rod, J, is attached to the other end of G.

it' are-the apertures for the passage of the steam from the main cylinder A to B.

K represents thc steam-ports, and y i L the exhaust-ports of the engine.,

The valve is operated by steam, whichV passes from the main cylinder through the apertures z', and drives the piston E one way or the other at the'complction of cach stroke.

4The.vibratingsr-lever G will'cause the valve to be reversed, when the passage z' will be closed, 'and the piston E will cushion on the back steam.-

The bars, num, ou the face of the valve, rwill close the exhaust-ports until the exhaust steam has acted on the'piston E and moved the valve, as described.

This improvement is designed more particularly for pumpingsengines, but it is applicable toV other engines.

. It will he observed that none but exhaust .steam is used inthe auxiliary cylinder, so that there can be no loss of power by thismethod of`operating the valve.- Y

We are aware of the patents granted to W. C. Wicks, for improvement in slide-valves, dated January 9, 1855, and George F. Blake, for improvements in direct-acting engines, `4and for improvements in steam-engines, dated, respectively, January 1, 186.7, and April 12, 1864, but as these patents do not show our arrangement of devices, they form n o part of our'invention; but

We claim'as new, and dcsireto secure by Letters. Patent- The arranenientA of the 4hars m m with the exhaust-openings L L and passages 'z', whereby to completeV the stroke ofthe valve C, so as to make the maximum opening of the ports, substantially as set forth.

L. H. ALLEN, JOI-IN B. WILFORD.

Witnesses:

WM. Pansen, WM. BARTON. 

